Glasshouse construction

ABSTRACT

A glasshouse construction, comprising a number of uprights which jointly support a light-transmitting roof construction and which, with the aid of girders, are connected in rows, and at least one screen construction, arranged between two successive rows. The screen construction is provided with a screen which is movable between a retracted position in which the screen is located as a package along a row of uprights and an extended position in which the screen extends substantially flat between two successive rows of uprights. At least one of the girders comprises a section having an open cross section, while in retracted position of the screen, the package formed by the screen is at least partly surrounded by the section.

[0001] This invention relates to a glasshouse construction, comprising a number of uprights which jointly bear a light-transmitting roof construction and which, with the aid of girders, are connected in rows, and at least one screen construction, arranged between two successive rows, having a screen which is movable between a retracted position in which the screen is located as a package along a row of uprights and an extended position in which the screen extends substantially flat between two successive rows of uprights.

[0002] In such a glasshouse construction, which is also designated as greenhouse, and which is well-known, the girders are arranged between the uprights, so that girders and uprights are located in one plane. The uprights and girders are designed as box-girders or thin-walled sections having an open cross section, since such sections are relatively light and, whilst having a relatively small cross section, can impart sufficient stiffness to the glasshouse construction. A small dimension of the cross section of the uprights and girders is extremely important in a glasshouse since the sections can cause light interception. Such light interception reduces the growth of plants present in the glasshouse.

[0003] The package as formed by the screen of the screen construction in the retracted position extends at the level of the girders, next to and along the uprights. The screen construction can be deployed, for instance, as a sun screen to temper the sunlight incident through the roof construction on the bottom of the glasshouse, as a thermal insulation cloth, or as a blinding cloth to prevent artificial light from exiting from the glasshouse through the roof. Usually, between all rows of uprights, screen constructions are arranged which extend throughout the length of the row, so that the entire floor surface, or roof surface, of the glasshouse, can be screened off. Optionally, there may be arranged several screen constructions, spaced apart in vertical direction along the upright, the screens of which each perform a specific function, for instance a shading screen and a blinding screen.

[0004] A drawback of the known screen construction is that in retracted position, it causes increased interception of light falling towards the bottom of the glasshouse when light is incident from above the screen construction.

[0005] The invention contemplates a glasshouse construction of the type mentioned in the preamble, whereby, whilst maintaining the advantages mentioned, the disadvantages mentioned are reduced. In particular, the invention contemplates a glasshouse construction with screen construction, whereby, whilst maintaining the simplicity and the stiffness of the construction, less cast shadow is caused.

[0006] To that end, the glasshouse construction according to the invention is characterized in that at least one of the girders comprises at least one section having an open cross section, which is located at the level of the screen, next to one or more uprights from a row and which extends along one or more of the uprights, and whose opening faces away from the one or more uprights, such that in retracted position of the screen, the package formed by the screen is at least partly surrounded by the section. What can be achieved by the use of a section having an open cross section as a girder next to the upright is that the screen package can be disposed at least partly within the cross section of the section, so that the light interception can be reduced. Such a section can be designed, for instance, as an I- or C-section, but is preferably designed as a U-section which is arranged along at least two successive uprights from a row.

[0007] Advantageously, one or more girders comprise two sections having open cross sections which are arranged with the open sides of their cross sections facing away from each other, on opposite sides of the uprights from a row. By placing two open sections next to the columns in mirrored relation relative to an intermediate plane, the resistance to torsion of the construction can be higher, while further two screens can be supported on one column.

[0008] What can be achieved by arranging the sections having an open cross section in spaced apart relation in the vertical direction of the upright is that in a simple manner two screen constructions located above each other can be arranged.

[0009] Preferably, the sections are designed with a U-shaped cross section and the sections have their back part, which connects the parallel legs, disposed against a side surface of at least one upright. However, sections having a C-shaped cross section can also be used.

[0010] When a girder is built up from two sections which are located on opposite sides of an upright, the girder can be elegantly stiffened further by connecting the sections with each other through a support construction. The support construction preferably comprises a lattice construction.

[0011] When the sections are spaced apart in the vertical direction of the upright, the support construction preferably connects the underside of the upper section with the upper side of the lower section. Advantageously, to that end, between the lower flange of the upper section and the upper flange of the lower section a number of diagonal stiffening rods are arranged, whose ends have been bent into a Z-shape, with ends of the stiffening rods extending transversely to the back of the sections, along the legs. Such a diagonal stiffening rod makes it possible, even when the girder is designed with an open section whose center of transverse forces is located outside the cross section, as with a U-section, yet to take up a relatively large transverse force load. This is advantageous in particular when cultivation troughs are suspended from the sections of the girder so as to hang clear of the bottom of the glasshouse.

[0012] In a particularly advantageous manner, one or more girders are designed as a construction element comprising two parallel extending sections having a U-cross section, which are spaced apart an intermediate distance both transversely to the back parts and transversely to the legs. If the length of the U-sections is chosen to be equal to the distance between the central axes of successive uprights, then, when the intermediate distance between the back parts corresponds to the width of the cross section of an upright, the construction element can simply be arranged between two successive uprights in a row while enclosing the uprights. The intermediate distance transverse to the legs then results in a spacing between the sections in the vertical direction of the upright. To further facilitate assembly, the construction element may be further provided with mounting plates which connect the sections in the manner of steps of a ladder. Preferably, the mounting plates are then set back with respect to the end of the U-sections over half the length of the cross section of an upright.

[0013] In a highly advantageous manner, the screen construction comprises a lead beam which is mounted on a movable end of the screen and whose length in the direction of the row is just smaller than the intermediate distance between two successive uprights of a row. Preferably, the lead sections are then connected through coupling pieces. The lead section is preferably a substantially L-shaped extruded section with an auxiliary chamber for receiving a coupling piece, while between the auxiliary chamber and a front edge of the lead section a chamber for mounting the movement mechanism is located.

[0014] Further advantageous embodiments of the invention are set forth in the subclaims. The invention further relates to a construction element for a glasshouse construction, to a lead beam and to an assembly of girders and uprights.

[0015] The invention will be further elucidated on the basis of an exemplary embodiment which is represented in a drawing. In the drawing:

[0016]FIG. 1 shows a cross section of a glasshouse construction according to the invention;

[0017]FIG. 2 shows a top plan view of the glasshouse construction of FIG. 1;

[0018]FIG. 3 shows a longitudinal section of the glasshouse construction of FIG. 1 along the line III-III in FIG. 1;

[0019]FIG. 4 shows a top plan view of the screen construction of the glasshouse construction of FIG. 1 in extended position adjacent an upright, and

[0020]FIG. 5 shows a detail of FIG. 3, including a cross section of the lead section of the screen construction of FIG. 4 in retracted position.

[0021] In the figures, the same or corresponding parts are indicated by the same reference numerals. The figures are only schematic representations of a preferred embodiment of the invention.

[0022] Referring to FIGS. 1 and 2, there is shown a glasshouse construction 1 comprising a number of uprights 2 which bear a light-transmitting roof construction 3. The uprights 2, as is usual in glasshouses, are spaced apart at uniform intermediate distances both in the longitudinal and in the transverse direction. The uprights are thus arranged, as it were, at the points of intersection of a grid made up of two groups of lines extending at equal intermediate distances and which cross each other. The distance between successive lines of the two groups can then be equal, but may also be different per group.

[0023] The roof construction 3 comprises a number of parallel extending gutters 4 which connect series of uprights with each other. Arranged between two gutters is a ridge beam 5 which is supported on the gutters 4 through rods 6. The rods 6, the ridge beam 5 and the gutters 4 jointly form rectangular support areas on which plates 7 from light-transmitting material, for instance glass, are supported.

[0024] The sidewalls of the glasshouse construction 1, which have not been represented in the figure for the sake of clarity, are likewise sealed with plates 7 from light-transmitting material which, as is known to those skilled in the art, can be supported by a framework of glazing beads arranged in front of or between the outermost uprights, whilst the glasshouse construction may further be provided with doors in the sidewalls.

[0025] The uprights 2, further, in a direction transverse to the series Rx as formed by the gutters 4, are connected in rows Ry by means of girders 8. In FIG. 1 two uprights 2 are shown in a row Ry extending in the plane of the drawing.

[0026] The girders 8, as can be properly seen in FIG. 3, are part of a prefabricated construction element 9.

[0027] The girders 8 are designed as two sections 8 a, 8 b having an open cross section. In particular, the sections 8 a, 8 b have the same U-shaped cross section, each having a flat back part 10 which connects two parallel extending legs 14 at right angles. The sections 8 a, 8 b each have a back part 10 a, 10 b disposed against a side surface 11 a, 11 b of an upright 2. The sections 8 a, 8 b are arranged in mirrored relation, so that their open sides 12 a, 12 b face away from each other. The sections 8 a, 8 b are each arranged next to the uprights 2 from the row, such that they enclose an upright 2 having a width b in the direction of a series Rx. The two sections 8 a, 8 b are connected by means of a support construction 13, such that the two sections 8 a, 8 b with the support construction 13 jointly constitute the construction element 9 which can be mounted as a pre-assembled unit between two uprights 2 of a row. In this exemplary embodiment, the support construction 13 is designed as a lattice construction which connects the lower leg 14 a of the upper section 8 a with the upper leg 14 b of the lower section 8 b.

[0028] The support construction 13 of lattice design accordingly connects the underside of the upper section 8 a with the top side of the lower section 8 b. Between the lower flange 14 a of the upper section 8 a and the upper flange 14 b of the lower section 8 b, a number of diagonal stiffening rods 13′ are arranged whose ends 13 a′ and 13 b′ have been flanged to form a Z-shape. The ends 13 a′ and 13 b′ of the stiffening rods 13′ extend transversely to the back of the sections, along the flanges 14 a, 14 b.

[0029] The length L of the sections 8 a, 8 b of the construction element 9 in the direction of the row Ry has been selected such that the sections 8 a, 8 b can extend just between the central axes of successive uprights 2 in the direction of the row. Adjacent the ends of the sections 8 a, 8 b, the sections 8 a, 8 b are connected with the aid of coupling plates 15 a, 15 b, like the steps of a ladder. With the aid of the coupling plates 15 a, 15 b, which, with respect to the end of the sections 8 a, 8 b, have been set back half the length 1 of the cross section of the upright 2 in the direction of the row Ry, the construction elements 9 can be secured against the sidewalls 17 of the uprights 2 by means of bolts 16.

[0030] The sections 8 a, 8 b are spaced apart a distance H in the vertical direction of the upright 2. The construction element 9 therefore comprises two parallel extending sections 8 a, 8 b having a U-shaped cross section, which, transversely to the back parts 10 a, 10 b, are spaced apart a distance b and which, transversely to the legs 14 a, 14 b, are spaced apart a distance H.

[0031] Between successive rows Ry of uprights 2, in each case two screen constructions 18 are arranged. The screen constructions 18 a, 18 b comprise a screen 19 a, 19 b which is movable between a retracted position, represented in FIG. 3, in which the screen 19 a, 19 b extends as a package P folded like an accordion, substantially along one row Ry of uprights 2, and an extended position, represented in FIG. 4, in which the screen 19 a, 19 b extends substantially flat between two successive rows Ry of uprights 2 in the direction of the series Rx. The screen 19 a which is situated most proximal to the roof construction 3 is designed in this exemplary embodiment as a blinding screen at the same time having a thermally insulating action, whilst the lower screen 19 b has a filtering or sun-screening action. The screen constructions 18 a, 18 b each comprise an upper support wire 20 a, 20 b to prevent the screen 19 a, 19 b from blowing upwards, and a lower support wire 21 a, 21 b, on which a lead beam 22 a, 22 b is supported which is attached to a movable end 23 a, 23 b of the screen. The lead beam 22 a, 22 b is coupled with a pull wire 24 a, 24 b or other kind of drive, for instance a rod or rack-and-pinion drive.

[0032] A fixedly arranged end 25 a, 25 b of the screen 19 a, 19 b is non-movably, fixedly coupled with the section 8 a, 8 b.

[0033] The support wires 20, 21 and the pull wires 24 of screen constructions 18 which line up in the direction of series Rx may be coupled and the pull wires 24 may be centrally operated.

[0034] As can be properly seen in FIG. 3, the package P formed by the screen 19 in the retracted position is at least partly located between the legs 14 of the section 8. The package P is therefore at least partly surrounded by the section.

[0035] The lead beam 22 has, in the direction of the row Ry, a length T which corresponds to the free intermediate space between two successive uprights 2 in a row Ry. The lead beam 22 has, in the direction of a series Rx, a length 1* which is greater than the length 1 of the cross section of an upright 2. The lead beam 22 is designed as an extruded section with an auxiliary chamber 26 for receiving a coupling beam 28, while the auxiliary chamber 26 is set back relative to the front edge 29 of the lead beam 22 whilst including the length 1 of an upright 2.

[0036]FIG. 4 shows, in top plan view, how two lead beams 22 are coupled by means of a coupling beam 28, so that the lead beams 22 and the coupling piece 28 can jointly enclose an upright 2 in the extended position of the screen.

[0037] In FIG. 5 the lead beam is shown in cross section. The lead beam 22 has a substantially L-shaped cross section and is designed as an aluminum extruded section. The lead section can be provided with a first chamber 30 for securing the movement mechanism, for instance for securing the pull wires 24 a, 24 b; with a stiffening chamber 31 and with an auxiliary chamber 26 for receiving a sealing strip 32 with which any chink between the front edge 29 of the lead section and a section 8 of a girder can be sealed. The auxiliary chamber 26 for receiving the coupling beam 28, whilst including the first chamber 30 for attachment of the movement mechanism, is set back relative to the front edge 29 of the lead beam 22 over at least the length 1 of the cross section of the upright.

[0038] The invention is not limited to the exemplary embodiment discussed here, but can encompass many variations.

[0039] Thus, the girder having an open cross section can be made of single design. Also, the girders can be constructed from several sections having cross sections of different size and/or shape. Further, the package that is formed by the screen construction in retracted condition may also be a roll. Further, in the vertical direction, more than two screen constructions can be used, or in the vertical direction only one screen construction may be used.

[0040] Such variants will be clear to those skilled in the art and are understood to fall within the scope of the invention as set forth in the appended claims. 

1. A glasshouse construction, comprising a number of uprights which jointly bear a light-transmitting roof construction and which, with the aid of girders, are connected in rows, and at least one screen construction, arranged between two successive rows, having a screen which is movable between a retracted position in which the screen is disposed as a package along a row of uprights and an extended position in which the screen extends substantially flat between two successive rows of uprights, characterized in that at least one of the girders comprises at least one section having an open cross section, which, at the level of the screen, is located next to one or more uprights from a row and which extends along one or more of the uprights, and whose opening faces away from the one or more uprights, such that in retracted position of the screen, the package formed by the screen is at least partly surrounded by the section.
 2. The glasshouse construction of claim 1, wherein the section having an open cross section comprises a U-section.
 3. The glasshouse construction of claim 2, wherein a back part of the section having a U-shaped cross section, which connects the legs, abuts against a side surface of at least one upright.
 4. The glasshouse construction of claim 1, wherein at least one girder comprises two sections having open cross sections, which are arranged with the open sides of their cross sections facing away from each other, on opposite sides of at least one upright from a row.
 5. The glasshouse construction of claim 4, wherein the sections having an open cross section are arranged in spaced apart relation in the vertical direction of the upright.
 6. The glasshouse construction of claim 4, wherein the sections are connected via a support construction, preferably a lattice construction.
 7. The glasshouse construction of claim 6, wherein the support construction connects a lower leg of the upper section with an upper leg of the lower section.
 8. The glasshouse construction of claim 6, wherein one or more girders are designed as a construction element which comprises two parallel extending sections having a U-shaped cross section, which are spaced apart an intermediate distance both transversely to the back parts and transversely to the legs and are connected via a lattice construction.
 9. The glasshouse construction of claim 8, wherein the construction element is provided with mounting plates which connect the sections adjacent their ends in the manner of steps of a ladder.
 10. The glasshouse construction of claim 1, wherein the screen construction is provided with at least two lead beams which are coupled by means of a coupling piece.
 11. The glasshouse construction of claim 10, wherein the lead beam is provided with an auxiliary chamber for receiving the coupling piece, which auxiliary chamber is set back relative to a front edge of the lead beam over at least the length of the cross section of an upright.
 12. The glasshouse construction of claim 1, further comprising a construction element for glasshouse construction, comprising two parallel extending sections having a U-shaped cross section, each with a back part which connects two parallel legs of the section, while the sections, with the back parts proximal to each other, are spaced apart an intermediate distance both transversely to the back parts and transversely to the legs, and the legs are connected via a lattice construction.
 13. The glasshouse construction of claim 1, further comprising a lead beam for use in the screen construction of a glasshouse construction, comprising an extruded section having a substantially L-shaped cross section and an auxiliary chamber for receiving a coupling beam which is set back relative to a front edge of the lead beam over at least the length 1 of the cross section of the upright.
 14. The glasshouse construction of claim 1, further comprising an assembly of girders and uprights, comprising a number of uprights which are arranged to bear a light-transmitting roof construction and which are connected in rows by means of girders, while at least one girder comprises two sections having open cross sections, which are arranged, with the open sides of their cross sections facing away from each other, on opposite sides of at least one upright from one row and are spaced apart in the vertical direction of the upright and are connected via a lattice construction. 